Brake mechanism



H. A. JOHNSON.

BRAKE MECHANISM.

APPLICATION FILED FEB. 15 1920.

Patented Oct. 31, 1922 fmabhmm 76 5 19/5 TTOR/VEVJ Patented Get. 31, 1922.

hllTlE ETATES HOWARD AACHEE JQH'NSON, OF NORFOLK, VIRGINIA.

BRAKE MECHANISM.

Application filed February 16, 1920.

To all whom may concern:

Be it known that I, Howano A. J OHNSON, a citizen of the United States, residing in Norfolk, county of Norfolk, and State of Virginia, have invented a new and useful Improvement in Brake Mechanism, of which the following is a specification.

My invention relates to band-brakes and is particularly adapted to be used in connection with electric motors for stopping the motor quickly after the current has been turned off. j

The principal object of my invention is to provide a brake and operating mechanism for motors and similar devices which. will be cheap to manufacture and maintain and which will be reliable and durable. Further objects of my invention will appear hereinafter, the novel combination of parts being pointed out in the claims. The preferred embodiment of my invention is shown in the accompanying drawings, in which:

Figure 1 is a side elevation of the brake and operating mechanism, part of the housing or frame being broken away;

Figure 2 is a sectional view thereof, taken on the line A-A of Figure 1, looking in the direction of the arrow; and

Figure 3 is a detail view of one feature of my invention.

Referring in detail to the drawings, 1 is a frame or base upon which both the brake and its operating mechanism are mounted. The base is provided with a U-shaped projection, 2, the arms of which are complementally drilled, as at 3. A lever, l, is ful crumed on a pin, 5, which passes through the apertures, 8. Attached to the upright portion, 1, of the base is a solenoid, 6, within which a plunger, 7, pivotally connected with the lever, 4;, at 8. is free to move vertically.

The shaft of the motor or other cont-rivance upon which the brake is intended to operate, shown at 9, is provided with a brake drum, 9, positioned to rotate above the lever. The brake drum is surrounded by a. resilient brake band, 10, provided with a suitable divided lining, 11, the ends of the lining being shown at 11 The band is of slightly larger diameter than the drum and is so constructed that it normally assumes a circular form. The ends of the band 10, are riveted as at 10 to members 12. which are separated by a block of hard wood, 13, to permit of adjustment of the brake band,a bolt 13 running through a curved plate or saddle, 14.

. the fulcrum,

Serial in. 359,014.

flanges on the members, 12, and also through the block, 13, to hold the band in proper position. Owing to the fact that the ends of the resilient metal band 10 are securely fastened together, the band 10 functions or operates in the same manner that a continuous band would do. Moreover band 10 and its lining 11 form a single brake unit. Riveted to the lower part of the brake band is The inner surfaces of the members 12 and 1 1,-i. e., those surfaces which contact with the band, 10,--form arcs of the circle assumed by the exterior of the band, 10, when it is not. distorted. The brake drum and brake band are so positioned that the center of the saddle lies above the lever, 1, a short distance from 5, of the latter. The lever passes between two apertured lugs, 15, which project downwardly from the saddle and a pin 15 passes through the lever and lugs so that the lever is pivotally attached to the saddle. The saddle, 1 1, is also provided with studs, 16, disposed in recesses, 17, formed by ribs, 20, on the sidewalls of the base, 1, as shown in Fig. 3. These studs function to hold the brake hand against rotation.

When the motor or other contrivance, to which the brake drum is alfia'ched, is started, an electric current is passed through the solenoid, 6; thereby drawing up the armature, 7, which in turn lifts the free end of the lever, 4L, as far as the limiting stop, 18, will permit. \Vhen the lever is thus raised, it also lifts the saddle, 14:, thus allowing the resilient brake band to assume the form of a true circle and to release its pressure upon the drum, the brake band taking the form shown in Figures 1 and 2 in which there is absolutely no contact between the brake lining and the drum. As long as the motor is in operation, the current through the solenoid is maintained, thereby preventing the brake band from engaging the drum.

hen the motor is stopped, the circuit through the solenoid is broken, and the pressureof the leaf spring, 19, forces down the lever and the saddle, 1e, thereby bringing the brake band in contact with the drum. Since the band is flexible this downward pull distorts it and the brake is brought into frictional contact with the drum throughout an a 'ipreciable part of its circumference. Although I have described only one form of my brake mechanism, it will be apparent to those skilled in the art that various modilications in detail and in the arrangement and combination of parts of my device may be made wlthout departure from my invention and also that my invention can be applied to any kind of apparatus requiring or employing a brake. I desire protection tor all modifications of my device that come within the scope of my invention as defined in the appended claims.

Havinr thus described my invention, I claim" 1. Brake mechanism comprising, in com-' hi ation a brake. drum, a functionally continuous brake band surrounding said drum and slightly larger than the latter, a saddle secured to said band, a. lever pivotally conected with said saddle, means associated with said lever for throwing; the band into frictional engagement with said drum, a solenoid, and a plunger therein connected with said lever whereby the operation of the plunger moves said lever to release said band from said drum, the said saddle having guide lugs thereon engaging suitable channels to prevent rotary movement of said band.

2. A brake mechanism comprising in comh the exterior of said band when free from strr v and an operatin; lever pivotally con nected to said plate.

ll. liralre mechanism comprising, in combination, a brake drum, a flexible brake hand siu'rouudingsaid drum, and slightly larger than the latter, a saddle secured to said haiuh a lever connected with said saddle, a spring associated with said lever, a solenoid a plunger therein connected with said lever, and a stop tor limiting the motion of aid levu. the V thereon enga rin suitable channels, all for the purposes descril'ied. at liralqe n1 rlianism comprising, in comhiuation. a brake drum. a functionally continuous resilient brake hand surroundingsaid drum and slightly larger than the latter. plates secured thereto, the inner surfaces of said plates having the same radius o'l curvature as the circle normally assumed hv the exterior (it-said hand and means for distorting said hand to force it into trictional engagement with said drum.

in lualre mechanism, a brake drum, a functionally continuous brake hand surrounding the same means connected with said hand to cause frictional engagement with said drunn and laterally extending;

adapted to work in suitable guide channels to prevent rotation of said hand but allowing radial movement thereof.

HOWAR l) AACHER JOHNSON.

vd saddle having guide 

